Selective time-limit controlling device for electric switches.



G. A. BURNHAM. SELECTIVE TIME L|M|T CONTRULUNG DEVICE Fon ELECTRICswncHEs,

APPLICATION FILED HJLY 2|. l9ll. REHEWE) MAY Il. 1918 J SHEETS-SHEET l.

Wzesses: 4 25M l T- O h a' 42. 5

I 74 61 il 73 4] 40 f f' ""Gf//zwfzlorr may G. A. BURNHAM.

smcuve TIME LlMn comnmuws nEvacE Fon ELECTRIC swncHEs. APPLICATION FILEDJULY 2|* 19H. HENEWEU MAY Il. lglB.' 1 ,288,502, Patented Dec. 24, 1918.

3 SHEETS-SHEET 2.

WL' fwsses; [Ime/250W f ma@ y fww G. A. BURNHAM.

SELECTIVE TIME UMhIT CONTRQLLING DEVICE FOR ELECTRIC SWITCHES.APPLIcATIon FILED xuLY 2|.|91|. RENEwEn MAY 11.1913.

1,288,502. Patented Dec. 24,1918.

3 SHEETS-SHEET 3.

all of UMTED STATES vPATENT onirica.

GEORGE A. BUNHAM, OF SAUGUS, MASSACHUSETTS, ASSIGNOR TO S. B. CONDIT,JR., 0F BOSTON, MASSACHUSETTS.

SELECTIVE TIMELIMIT CONTROLLING DEVICE FOR ELECTRIC SWITCHES.

Specification of Letters Patent.

Patente :l Dec. 24, 1918.

Application tiled July y21, 1911, Serial No. 639,763. Renewed Kay 11,1918. Serial No. 234,015.

To all whom it may concern:

lie it known that l, (EonoE A. BURNHAM, a citizen of the United States,residing at Saugus, in thc county of Essex and State of Massachusetts,have invented an Improve# nient in Selective Time-Limit ControllingDevices for Electric Switches, of which .the following is aspecification.

This invention relates to time-limit controlling-devices forelectric-switches. Heretofore time-limit controlling-devices `for`electric-switches huw .been devised including operatingmeans for theswitch requiring a prolonged period of time to operate the switch. Insome instances, the ,time-con trolled element of the operating-means ismoved at a constant speed through a definite interval of space, hence,the period of time consumed by it is the same regardless of the strengthof the overload. In other instances the time-controlled element is movedat af varying speed according to the strength of the overload, so thatthe period of time consumed by it varies according to the strength ofthe overload, being less on' a heavy overload than on a light overload.Furthermore,

the operating-means for the switch has been made manually adjustable sothat the timecontrolled element is moved throu h an iny tcrval of sacc'o greater or less ength in operating t ic switch. So far as I amaware,

these controlling-devices made by others have failed to be' selective inaction,

notwithstanding their different normalsettings, upon the occurrence of avery heavy overload, as, in such case, they will all operate theirrespective switches simultaneously or substantially so and unnecessarilyopen the circuits.

This invention has for its object the construction of a time-limitcontrolling-device for electric-switches having operating-means for theswitch which requires a prolon ed period of time to operate the switch,ut which is adjustable automatically to vary said period of timeaccording to the strength of the overload. My present invention isapplicable to either type `of controlling.- device above referredto,v,and for: purposes of illustration both forms of controlling-de#vices are` here shown, one wherein the timecontrolled element iscontrolled by the overload cin-'rent and moved at a constant' speed,

and the other wherein the time-controlled element is controlled by theoverload current i troller for the switch and and moved at a speeddependent upon the strength 'of the overload, up to'a predeterminedcurrent value, and on overloads of higher currentl values is moved at aconstant speed regardless of the strength of the overload, so that inany event'ay prolonged period of time is maintained. For preference Ialso select a type wherein the operatingmeans is manually adjustable tovary the period of time consumed by it in oper .ting the switch, so thateach time-limit controlling-device may have a dijtl'erent normal settingfrom others4 which are arranged in the circuit. i

In the present embodiment of my invention automatic variation of theoperating means is accomplished by varying the length of the interval ofspace throughwhich the timecontrolled element4 moves, by meanscontrolled by the overload current, but my invention is noty limited to-accomplishing this result in this manner, as I desirer to includewithin the spirit and sco e of my invention any means to automatica] yadjust said operatmgmeans to vary the time consumed by itin completinits operation tooperate the switch, which 1s controlled by theoverloadcurrent, and, especially when said o eratingmeans is also actuated bythe overoad current. 4 In the present embodiment of myinvention theoperatingmeans comprises ,a conan operatingdevice for said-controller,and said control- `ler comprises an 'electro-magnet to operate theswitch., and the o erating-device comprises a cifcintcloser fldr thecircuit'of-'said' electro-magnet, both members of said` cir-.cuit-closer being movable toward and from the other, movement of onemember bein 4automatically controlled by the overload current to varythe other member,v to reduce the intervalof! s'pace alnd,correspondingly reduce theV time required ffm; 'the mem rs to enga-geajdgclose theil-,cuginit`l `of the controller to operate theoa'llgcli,"while the other member is' operated by .an electric-motor,controlled .bythe overload, at a constant or4 variable speed accordingto the construction of the motor, or according to the current-value ofthe overload.

Figure 1 is a side elevation of a time-limit controlling-device forelectricswitches, em bodying this invention.

its position with Arespect to elevation of the motor and circuit whichmay be employed.

F ig. 5 4is a detail of the operating-means foi' the switch and adiagram of a modified form' of electric-motor and circuit which miy beemployed.' 4 y eferring to Fig. 4, wherein a single linccircuit is shownas a simple in anner of illustrating niy invention, 20 represents, thecircuitV or 'line 'wire, `end 21,' a switch of anysuitableieoiistriictioin but preferably of a type adapt'edto beioperated automatically to open thecircuit, and inanuall to close thesame. A snap-switch of usua construction is here shown,'he'viiig ahand-lever 22, and an' iictuating-spriiig :23. This is the switch whichthetime`li|nit -controlling-device forming the subject-matter of thislapplication designed to' operate aut'oniatically,toopen the iciicuit20.The time-limit controlling-device involves operating-means fo; theswitch` and `means responsive to an overload current to actuate it, orto control its operation, and means also responsive 4to theoverloadcurrent to adjust itwhereby thel period of time required for it"to`operate the switch is 'reduced accordingh strength ofthe current. Asheres own for' the purpose of illustrating my invention controller of theelectrica y type, which is adapted,` when operated,to open the switch,and an'op'erating-devi .fortheircuit of said switchecontroller, which'requires a prolonged period of .time to complete its operation tooperate the switch-controller, and

,said Voperating-meansk com 'rises e switch.

said operating-device is,l automatically ad' V `justecl byl Ineensresponsive to the. overload current, and isalso actuated by meansire-Vsponsive to theoyerloiid. current.

1 The switch-controller here4 shown consiste of an electro-magnet 24,,connected in a batterycircut 25, the, armature of which is'connected toa lever.28,'secured to e pivotshaft,"'and to saidfshaft is secured a'Short ari'n'- 291 which is designed to engage` and operate e snap-switchto open' the`circiiit 20,Uupon energization of ,the magnet,

4The operatingdevicegfor the switchcontrollerfs-here shown, consists ofa -circuit controlling-device. for the circuit 25. Lsaid ,eircnitfcontrollingrdevice coinp1'ising` two members, both ofwhich aremovubleto'wiird and from each other, :and yone,,of, tlie'iiiii-itime-controlled, sou's to'.' require a prolon "ed period of time to moveand engage the ot er ,.niember.l 4 One of said circuit-closing meinbers'comprises'two circuit-'contacts 2Q, 27, adapted .to be connected withthe circuit 25, and said'contacts are arranged on au-arnr 30, ofinsulating material, secured to a pi\otshat't 31, bearing a pinion 3'2,which is in mesh with a toothed-sector 33, pivoted Aat 34, and connectedh v a link 35, with the armature of a solenoid 75. which armature isshown in Fig. 1 asin its normal elevated position, and in Fig. -t asmoved downward in response to the pull of the winding of tlul solenoid.Said solenoid is included iii a circuit 70, of the secondary-coil Tl, ofa transformer, the |n'imary-coil 72, of which is included in the circuit20, so that said solenoid is responsive to an overload upon the circuit20. which is reduced hy or through a transformer. Said solenoidconstitutes the means which is responsive to an overload-current andwhich is employed to adjust the. operating-ineans for the switch, bymoving the circuit-closing niember 26, 2T, so as to vary its distancefrom (he coperating circuit-closing member. accordin to the movement ofthe armature of the soenoid. On a light overload said circuitclosing.member 26, 2T, will bc moved coun ter-clockwise a short distance, asshown in Fig.4, and on a heavy overload, will-lic. moved acorrespondingly greater distance, although it will hc understood thatmovenient of the core of the solenoid is checked when it arrives at. orabout the middle of the winding of the solenoid. The coperat ingcircuibclosing member of the circuit- `elosingdevicc is time-controlledand consists'of a yoke or arm 40, arranged to be moved rotai'il ina-vertical plane, having at" its extremity fi cross-piece or pin 41,

which, when the :Deke or arm arrives at the end 'of its rotar),ymovement is adapted to cngage the circuit-contacts 26, 27, 4to therebyclose the circuit 25 of the switch-controller.

Said yoke or arm is mounted loosely on a shaft 42, to which aworin-wheel 43, is secured, and means, as a screw 44, is provided ,foradjusti'ibly connecting said yoke or arm ielii'tiveihereto. jAs theworm-wheel is re- Avolved in' tlie'direction of the arrow Fig. 1,' saidyoke or arm ismoved by it through au iiitervul of space, which isvariable in length according to.' its connection with the worm wheel toengage the circuit-contacts 2li, 27, and the relative position of thecontacts 2e, 27.

The Vmovement' of thc worm-wheel and yoke or arm to close the circuit25, of the switch requires a prolonged period of time and suchmovement'is controlled by means responsive to the overload, so that saidcircuit-closing nember is controlled by the overload current.

As a means to move the \vormwhecl and the yoke or arm an electric-motoris cmployeft In Figs. 1 to 4 inclusive, the electric-1no tor isconstructed and arranged substantially the same as shownin my LettersPatent, No. 1,011,716, dated October 15, 1912, if being of the seriestype or having the gcneral characteristics of a series motor, andconstructed and arranged in such manner that its magnetiocircuit aiidwindings are so proportioned as to require an overload of approximatelythree times the full load of the circuit controlled by the switch tocause the motor-armature to attain its speed-li1nit,

although a lesser overload will cause the motor-aru'iature to revolve ata slower speed proportionate to the strength of the over load, and agreater overload, meaning an overload in excess of that requiredto causethe motor-armature to attain its speed-limit will cause themotor-armature to revolve at its maximum speed regardless of thestrength of the overload. Said electric-motor is included in atransformer circuit 70, so as to be responsive to thc overload, beingcontrolled and operated by it. In Fig. 5 I have 4shown an ordinary constant speed motor connected in a battery circuit, which is controlled bythe overload current but operated by thebattery current. So far as mypresent invention is concerned, either type may be employed or any otherSuitable type, as the variation in the pilolonged period of timeconsumed by the timed-element of the `operai;ing-means is automaticallycontrolled by means independent of the motor and is operated or controlled by the overload. i Referring to Figs. 1 to 4, 48 represents thearmature of th motor, which is supported in suitable bearings, and oneend of the shaft of the armature is extendedas at 49, and is threaded toform va Worm. The worm-wheel 43 is arranged beneath said worm, but isnormally out of engagement therewith, and is supported by a movablt`member whereby it is movable into and out of engagement with said worm.Said worm serves as the means to drive the worm-.\vheel.

and therefore, constitutes the actuator for` the operating-device. Theengagement of 'the operating-device with its actuator is con'- trolledby the current which operates the motor, and herem said worm-wheel 43,1s

supported by an extension of the lower 'part of the ieldframe of themotor, which is made movable with respect to the upper part thereof,whereby the worm-wheel is moved into and out. of engagement with itsactuator. The field-frame of thc motor is or may be made in two parts,or mav ha vc a Inovable part in connection with it` and` as bertlshown.4 said frame is divided on a horizontal line, representinglr theupper part and 5ll thc lower part` and said parts art` hingcdlyconnected together at 52, so that the lower part is movable toward andfrom the upper part, and the upper part is hcld slationarilv by beingconnected to the support 53. With the exception of making thcfield-frame in two parts it may bc constructed, generally speaking, inany \\'clllnio\\'l or suitable manner, to support the field-coils.Movement ofthe lower part 51 in a direction away from the upper part islimited by au adjustable yielding stop comprising, as shown in Fig. 1, apin 55, extended through an ear 56. arranged thereon, which engages aspring 57, resting against a fixed. abutment 58, which may be adownwardlensio'n ot' the upper part. The lower end of the ear 56 has ahole through it for a bar (it), which is horizontally arranged andsecured to thc extension' 58, and which projects through said holel fora considerable distance, and a. i

spring 59 is arranged on said bar between the ear and a nut (51,adjustably connected with the bar, whichA exerts its pressure upon theear in a direction to move the lower part of the frame downwardly, andupward lnoveinentoftlle' fraaie acts to compress said spring so thatsuch movement is rcsisted by the spring, and by adjustment.

ofthe lspring greater orlcss force may' be required to lift the frame.The bar 60 may be calibrated. if desired, to indicate in amperes theforce required to lift thel frame by the magnetic influence. due `to thecurrent traversing the field-coils ot' the motor, and the motor to actas a magnet. Thus 4the spring 59 not only acts as a retractile spring toassist gravity in moving the part 5l away from the part 50, but. alsoimay be employed to determine the energy required to lift it, and henceserves as au adjusting-device foi-,the motor, whereby it, may be causedto move the operating-deviec into engagement with its actuator upon anoverload of a given value, or in excess ot' said value. 'hen the lowerpart of the field-frame is in its lowermost position. being removed fromor remote from tht` upper part` as represented in Fig. 1. said wormwbcelis removed from engagement with the' worm` and when said lower part oftlr: field-frame is in its uppermost position, as represented in Fig. 3,said \\'orm-wln\el is in engagement with the worm.

The motor is or may 'be arranged in the transformer circuit T0. but is`normally short-circuiied by a switch or circuit closer, the fixedmembers 7?), of which are en gaged by a plate T4, connected with thcannature ot' the solenoid 75. When said sole.-l

noid pulls down its armature due to-an overload on the circuit 2U, thecircuit-closer 73, Tt, will he operated to open the shortcircuit of themotor. as shown in Fig. 4. so that the motor will be operated 'by theoverload current, through' the transformer; and the lower part of thelieldvframo will be attracted toward theI upper )art thereof to movet'he operating-device or the 'switchcontroller .into engagement with itsactua tor: and the arm 4U will be moved rotarily cloelnvise toward andinto engagement with the cireuit-contzu-ts 2G. 2. to cause the switchcontroller to operate the switch and open the circuit :20. ln case theoverload eurrentvpasses over the circuit for a short period of time andthen ceases, and such period ot' time is insullicient to move theoperatiiig-device far enough to cause. its arm l() to engage thecircuit-contacts 26, 27, then as soon as said overload ceases the partswill be restored to normal by gravity. The, distance which the arm 4Umoves depends upon the position of the circuit-contaets 2G, 2T. withrespect thereto, and the posit-ion of said contacts is controlled by theoverload through the 'solenoid 75. to thus control the length of theperiod o f time. By controllingr thc length of the prolongedpe- .riod oftime. required for the operatingmeans to operate; the switch by meansoperated by th'c overloadis of the greatest importance, as it enables aset of time-limit controlling-'devices to be selective regardless ofthe. strength of the overload.

By the means shown iu Figs. l to l. the. variation in thc'pe-riml o-f`time, occurs at both ends thereof, as for instance. the movement of thearm 40 is varialblc according to theeurrent value yof the overload u) toa predetermined current value. and is t elinite. o n overloads of highercurrent values, and theJ distance said arm. nuves is variable accordingto the position of the arlu 3() bearing the contacts` 26,27. amlmovement of said arm 30 is variable according to the. current value ot"the overload u i to a predetermined current value` and is del'inite onoverloads of higher current values. 'l`he re-latively stationarycontact-memher Il() will onl \I approach the retarded contact-lnem'berl0 a limited distance, so that in any event.

with a given setting of each relay., there.-

will be a certain pcriodof time elapse. het'weml thc occurrence of theoverheid and the tripping of the circuit-hrenker. which will he constantfor each Arelay above 'certain values of overload. and lio-matter howmuch higher the'ovexfload may he. and also difierent for each relay inthe. system according to' its setting. This result will be obtained alsoby the form of ap iaratus shown in ,Fig 5, and with either orm ofapparatus the ohartlincs will he Indicated by inverse,

curves followed bylstraight lines, which will not intersect on a heavyoverload, as for instance, on an overload in excess of three times thefull load of the current which is controlled by the switch. The form ofapparatus shown'in Figs. 1 to -l has the advan- ,tage over the formshown in my patent;

aforesaid of providing a very short movement for the contact-member 40,upon the. occurrence of a .Very heavy overload, so that a very shortperiod of time is consu-med, althouvh such period of time is of asubstantia yet of definite length, while with the motor of the patent,said contact-Incinber l() moves through thel same arc on both heavy andlight overloads, its speed -of movement bolug greatly accelerated onheavy overloads thus the motor in the present form of apparatus needn'ot have as wide a ran of flexibility.

Re crring to Fig. 5, the electric-motor may be constructed tie same asthe motor shown in Figs. l and 2, with the exception that itsmafrnetic-circuit and windings are proportioned as usual inelectric-motors, so that it. is arranged to bc operated at. a constantspeed by a battery current or other source of energ In said Fig. 5, theelectric-motor is arranged in a battery-circuitl 90. which is closed bythe circuit-closin members 73, 7l. controlled by the solenoid T5. sothat upon Ithe occurreneeof an overload. said battery circuit is closedand the. motor is caused to operate at a constant speed to more the arlnat() clockwise at a con- 100 stantl speed, but the distance said armmoves is varied b v means controlled by the solenoid T5. which meanstogether with the solenoid are substantially the sameC as. shown in Fig.

l. so that the'saine result'is obtained, al- 105 though the variation inthe prolonged period i of time occurs at only one end of the period,said variation being produced by thc'action of the solenoid in responseof an over-load.

'l`he constantspeed-motor, being included in 1,10

a lmtter v,circuit or driven .by an independent. source of electricenervy, might itself act as a definite timc-lii'uit relay, babas hereshown. it will not operate the switch-operating means 'except inconjunction with the 115- solenoid by which the time of operation isvaried.: cording to the current value of the overloiilldnp to anoverload of a predetermined carrait value. and by which the time ofoperation will be. definite' on over- 120 loads ofhigher current values.Hence,"inv the forni of apparatus shown in Fig. the elia-rt lines 4will:be 'indicated by inverse curves of a pitch sliglxtlyditf'ering fromthat of the aforesaid apparatus,"and then'by 125 straight' lines whichwill not intersect on heavy overloads. ln said Fig. 5, the. plate4 74'.normally occupies a position above the contacts 73, and w'ill be moveddownward into engagement with said contacts upon a 130 downward movementof the core of the solenoid. and in view of the fact that engagement isrequired upon the occurrence of a light, as well as a heavy overload,said plate is loosely arranged on the stem connected with the core ofthe solenoid, and is held b v a spring'so that movement of the core ot'tbesglvenoid independently of the plate is permitted"upon the occurrenceof heavyv overloads` while the plate is engaging the contacts T3. Uponthe occurrence of a light overload. the core will be moved a shortdistance suflicient to cause the plate Tt to engage the contacts 73. andthe arm 50. to be moved counter-clockwise a short distance only.asrepresented in Fig. and upon. the occurrence otl a heavy overload, thecore of the solenoid will be moved farther, but the plate il will stillengage'said contacts and will there remain while the core movesindependently of it; although downward movement ot' the core is limited.as here shown, when it arri ves at or about. the middle of the solenoid,and will not be moved fartherrre-l gardless of the strength of theoverload. This form of apparatus, shown in Fig. wherein a constant speedactuator is employed for one of the contact-members, and a variableactuator employed for the other contact-member, which variable actuatoris arranged to be controlled by an `overload current in the mannerherein set forth, forms the subject matter of a divisional applicationNo. 873,062. tiled November 19, 1914.

In lieu of employing an elcctric-motor to operate the operating-meansfor a Switch, any other suitable device may be employed. which iscontrolled by an overload current, and is arranged to operate saidoperatingmeans at a variable or constant speed or both.

adjust one of lsaid members to reduce said period of time according tothe strength of the overload` and means controlled by the overloadcurrent to actuate the other member :it a variable: speed according tothe strength ofthe overload, substantially as dcscribed.

ln a selective time-limit controlling-device for clcctrioswitches, thecombination of switch operating-means requiring a prolonged period ot'timcto operate the switch, including cooperating contact-members. meanscontrolled by au overload current t0 adjust one of said members toreduce. said period of time according to thc strcngth'of thtI overload,and meansl controlled by the overload current to actuatc the otherlilcincontact members, means controlhal by an overload current to ladjust one of said members to reduce said period of time'according tothe strength of the overload. and an electric-motor controlled by theoverload current to actnate the other member at a variable speedaccording to the strength of the overload. substantially as described.

4. ln a selective time-limit controlling-device for electric-switches,the combination of switch operating-means requiring a pro- -longedperiod of time to operate the switch, includingl cooperating contacti'nembers, means controlled by an overload current to adjust one of saidmembers to reduce said period of time according to the strength of theoverlo d. and an electric-motor c0i1- trolled by lhe overload currentwhich is constructrl and arranged to actuate tlieother member at avariable spoed'according tothe current value of the overload up'to apredetermined current value and at a definite speed ref'ardlcss of thestrength of the overload on iigher current values, substantially asdescribed.

ln-a selective time-limit controllngfdevice for electric-switches, thecombination of switch-operating-mcans requiring a pro` longed period oftime to 'operate the switch, including cooperating contact-members, 105means controlled bylan overhaul in'rcnt to adjust/one of said members toreducefsaid` period of time according tothe Vstrclncrth of the overload,and means controlled by the overload current to actuate the other lmem-110 ber. at a variablesspeed according to tho strength of the overload,lboth membersl being permitted to return to noi-malimmediately uponcessation of the overload, substantially as described.

6. A selective timclimit controlling-device for electric-switchesincluding a. controller fortho switch, an `operating-device for' saidcontroller comprising Vtwo members, onle ofwhiehhis time-co`ntrolled',means con: 120 trolledy by `a| oyerloadwalrrent to actuato saidtilnefcontrolled` member at a variable speed according to tho strengthof the overload, and means controlled by the overload for saidcontroller comprising.r two members, one of which is time-controlled,means controlled by an overload current to actuate the timewontrollcdmember at a variable speed up to a predetermined current value and at udefinite .speed on higher current values, and means controlled by theoverload current to movc thc other member toward the time-controlledmember, Substantially as described.

8. .selective time-limit controlling-devicc for electric-switchesincluding` a con troller for the switch, an operating-device for saidcontroller comprising two members, one of which is time-controlled, anelectricmotor controlled b v the overload current to actuante saidtime-controlled member, and means controlled b v the overload lcurrentIto more the other member toward the timecontrolled member, substantiallyas described.

9. A selective time-limit controlling-device for electric-switchesincluding a controller for the switch, an operating-device for saidcontroller comprising two members, one of which is time-controlled. anactuator into and out of engagement with which said time-controlledmember -is movable, means controlled by the overload current to movesaid time-controlled member into and out of engagement with itsactuator, means con trolled `by .the overload current to drive saidactuator, and means controlled by the overload current to move the othermember toward the time-controlled member, substantially as described.

10. A selective time-limit controlling-device for electric-switchesincluding a controller for the switch, an operating-device for 'saidcontroller comprising two members, one of which is time-controlled, an'actuator into and out of engagement with which said time-controllermember is movable, means controlled by 'the overload current to movesaid time-controlled member into and out'of engagement with itsactuator, and an electric-motor controlledl by the overload currenttodrive said actuator, and means controlled by an overload current tomove the other member toward the 'timecontrolled member, substantiallyas described. C

11. A selective time-limit controlling-de` vice for electricswitchesincluding?. a controller for the switch, an operating-device for saidcontroller comprisin two members, one of which is time-control ed,`means con'- tr'olled by an overload current to move one' of said memberstoward. the other to' redute the time requiredfor the timecontrolledmember4 to complete its operationfmearis to .adjust one of the membersto vary the len th of said' period of time, and meanscontrol ed by anoverload current to actuate the timedescribed.

controlled scribed.

12. A selective time-limit 4controllingzfdcvice for electric-switchesincluding an electro-magnetic controller for the switch. ncircuit-closing device for thc circuit of said controllercomprising twomembers, one of which ie time-controlled, means controlled by anoverload current to move one of said mcmbers toward the other to reducethe time required for the members to engage, und means controlled by theoverload current to more the time-controlled member, substantially asdescribed.

13. A selective time-limit contrr.)llin, lcvice for electric-switchesincluding un electro-magnetic controller for the 'switch` acircuit-closing device for'the circuit of said controller comprising twomembers, one of which is time-controlled, means controlled by anoverload current to move one of said members toward the other to reducethe time requiredfor the members to engage, means to adjust one of themembers tovary the length of said period of time, and means controlledby the overload current to move scid time-controlled member,substantially as de scribed.

14 A selective time-limit controlling-de- -vice forelectric-switchesincluding an electro-magnetic controller for theswitch, a ci rcuit-closing device for the circuit of said controller, asolenoid responsive to an overload to` move one member of said'circuit-closing device toward the other member, and means controlled'by the overload current to more said other member toward the firstnamed member to close the circuit` substantially as member.substantially as de- "hoid responsive to an overload to move 'onetro-magnetic controller member o'f said circuit-closing device for wardthe other, and an electric-motor rc3, sponsive to the overload tomovettbc cotleiff m'ember toward the 'first named men'i'ber closedecima, Sebstancniy as desd-inea.

16. A selective time-limit controlling-db vice for electric-switchesincluding a ebntroller for the switch, a circuit-closing device for thecircuit of said controller, a solo1 noid responsive to an overload tomove one member of said circuit-closing` devicctoward the other, and anelectric-motor responsive to the overload to move the other membertoward the fist named member to close the circuit at a' speed dependentupon the strength of the overload, substantially as describ d.A

17. A selective time-limit controlli11g-dcn vice forelectric-s|witchesincluding an elecfor the switch, a circuit-closingdevice for the circuit of said controller, means responsive to anoverload to move one member of said circuit-closing device toward theother member to reduce the time required for the members to engage. anactuator for the other member into and out of engagement withwhich it ismovable, meansI controlled by the overload to move saidotlier memberinto engagement with its actuator, and an electric-liiotor to drive saidactuator, substantially as described.

18. In a selective tiiiie-liinit controlling device forclectric-switclies. the combination of switch operatinganeans includingmovable cinitacbniemltx'rs. one of which is time. controlled, meanscontrolled by an overload current arranged to actuate thetinie-coiitrolled member at a speed proportional to the current value ofthe overload up to a predetermined current value and at a definite speedon overloads of higher current values. and means controlled b v theoverload current to move the other member toward the time-controlledmember varying distances according;` tothe current value ofv tbe over;load up to a predetermined current value. and definite distances onovcrloads of higher current values, substantially as described.

19, In a time-limit controlling-device for electric-switches,- thevcombination of switch operating-means including movable contaetmembers,one of which is tinie-contrt'illed` and means responsive to andcontrolled by an overload current to move the vother inember toward thetime-controlled member a' variable distance according to the currentvalue of the overload up to a predetermined current value, and adefinite distance on overloads of all higher eilrrent values, and,

means to move the time-controlled membriinto engagement with the othermember in any position it may occupy. providing overload conditioncontinues, substantially as dcscribed.

20. In a time-limit controlling-device for electric-switchcs, thecombination of switch .operating-means. time-controlled means associatedtherewith including two contact members, a solenoid also'associat-edwith said switch opcratingmeans, thecorc-piecc of which is movable inresponse to an overload a variable distance according to the strength ofthe overload, np to a prede-termined current value, and is movable itsmaximum distance on all overloads of higher current values tocorrespondingly move. one of the contact members, and means to move theother ciuitziet-member into engagement. with the aforesaidcontactinember in any position it may occupy. upon the continuance ofabnormal conditions, substantially as described.4

2l. The combination with an electrical installation, of a relaycomprising a movable member. means whereby said member is moved at aspeed which varies as a direct function of the rate of flow ot currentin said installation, and means copcrating with said movable member forinterrupting the How of current in said installation when said memberhas moved from an initial position a distance which is an inversemeasure of the rate of flow of current in said installation.

22. The combination with anelcctrical installation, of a relaycomprising a movable member. means whereby said member is moved at aspeed which varies as a direct function of the rate of How of current insaid installation, a second movable lmember arranged to move toward andin the path of movement of said first mentioned movable member, meansfor moving said second meniber tow: rd said first mentioned member a`distance which is a direct' function of the lrate ofiow of current insaid installation, and means controlled by the engagement of saidmembers for interrupting the How of current in said installation.

..3. The combination with an electrical installation, of arelaycomprising a movable member, means adapted to novc said member at aspeed which varies as a direct function of the rate ot' tlow of currentin said installation, means for causing said last mentioned means tomove said member when the rate of fiow of current in said installationexceeds a predetermined amount, and means cooperating with said movablemember for interrupting the How of current in said iii stallatioii whensaid member has moved a distance which is an inverse measure of the rateof flow of current in said installation.

24. The Combination with an electrical installation, of a relay,rcomprising a movable member. means adapted to move. said member at aspeed which varies as a direct func tion of tbe rate offtlow of currentin said installation, means for causing said' last mentioned means tomove said member `when the rate of How of current in said installationexceeds a predetermined amount-.a sec. ond movableinember arranged inthepath of movement ofsaid first mentioned mem ber, means for movingsaid' second member toward said first mentioned member a distance whichis a function of the rate ot flow of current, and means controlled bythe engagement ofsaid members for interrupting the How of current insaid installation.

25. The combination with an electrical in,- stallation. of a relaycomprising a movable member havingan initial position, means adapted tomove said member at a speed which varies as a direct function of therate of How. of current in said. installation` means for causing saidlast mentioned means to lit.

move said member when the rate of flow of current in said installationexceeds a predetermined amount, means adapted to return said movablemember to its initial po sition when the rate of How of current is lessthan said predetermined amount, and means cooperating with said movablemember for interrupting the flow of current in said installation whensaid member has moved a distance which is an inverse measure of the rateof How of current.

26. The combination with an electrical installation, of a relaycomprising an electric circuit, a movable contact in said circuit, meansadapted tomove said contact at a Saeed which varieslas a direct functionof the rate of llow of current in said installa tion, means for causingsaid last mentioned means to move said member when the rate of fiow ofcurrent in said installation exceeds a predetermined amount, a secondmovable contact in said circuit arranged in the path 'of movement ofsaid first mentioned contact, means for moving said second contacttoward said first mentioned contact a distance .which is a function ofthe rate of flow of current, and means controlled Vby the en-'.gagementof said contactsfor interrupting the ,flow of current in saldinstallation. 30,

27..The combination with anelectrical installation, of va relaycomprising electromag- ,netc'means electrically connected totheinstallation and adapted 'to produce a n1agl "netc field proportional tothe rate of flow vof ncurrent in' said installation, an armaturerotatably mounted in said magnetic field, a movable memberadapted to heoperatively connected to said armature when the rate of flow of currentin the installation exceeds a predetermined amount, and means cop-.yerating with said movable member for in- `terruptmg the flow ofcurrent in said 1nstallation when said member has moved a distance whichis an inverse measure of the Ainstantaneous rate of flow of current.

28. In combination with an electrical in- `stallation, of a relaycomprising electromagnetic means electrically connected to theinstullalion und adapted to produce a magnetic. field proportional tolllc rate of ll'ow of cm'- rcn( in said installation1 an urnnitnrcrotatably mounted in said magnetic field. n movable member adapted to beoperatively connected lo said '.lrnuiture when thc rato of flow ofcurrent in the installation exceeds a predetermined amount, a secondmovable member arranged in the path of movement of said lirst mentionedmember. means for movin#r said second member toward .said firstmentioned member n distance which is a function ol' the inslantancmlsrate of flow ot' current in thc installation, and means controlled bythe engagement of said mom bers for interruptingr thc ilow of current insaid installation.

ifi. 'l`llc combination with an electrical installation. of a relai'comprising;A two cooperating movable members. means for moring one. ofsaid members toward the other member at a speed which is a directfnuction of an electrical rlmractelistieY ol the in stallation, meansfor moving the other mem` ber toward its cooperating member a distancewhich is a function of an electrical characteristic of the installation,and means controlled by the engagement of said members for interruptingthe liow o current. in said installation.

30. A relay comprisingV in combination an electric circuit, two movablecircuitI closing,r contacts included in said circuit, means for movingone of said contacts toward the other contact at a speed which varies asa fuuction of an electrical characteristic of an electricalinstallation, and means for moving the other contact toward itscoperating contact a distance. which is a function oi an electricalcharacteristic of the installation.

ln testimoni7 whereof. I have signed my name to this specification, inthe presence of twosubscribing witnesses.

GEORGE A. BURNHAM.

lVitnesses t B. J. Norms, lol. B. DAVIS.

